1. Field of the Invention
This invention relates to user interfaces and, in particular, to a pushbutton user interface that enables a user to preview the effect of activating a pushbutton before the pushbutton is actually activated.
2. Related Art
Pushbuttons provide binary control. Often, it is desirable to know what effect activating a pushbutton (i.e., actuating the pushbutton in a manner that produces the functionality associated with the pushbutton) will have before the pushbutton is activated. If the function of the pushbutton is constant, such as power on/off, the result of activating the pushbutton can often be known beforehand. However, if the function of the pushbutton can vary (such as is the case with a set of pushbuttons used to select preassigned radio stations), the result of activating the pushbutton may not be known with confidence beforehand. In such cases, it can be desirable to know what effect activating a pushbutton will have (e.g., which radio station a pushbutton will select) before committing to the activation. In particular, in a pushbutton user interface including multiple pushbuttons, it can be desirable to know what effect activating a particular pushbutton will have before the pushbutton is activated.
Graphical icons formed on, or attached to, pushbuttons have been used to explain the behavior of pushbuttons on devices such as remote control units. However, graphical icons can be confusing and non-intuitive, particularly when used to explain specialized functions.
A “mouse rollover” is a technique that has been used within the software user interface of a computer to explain the behavior of components of a graphical user interface of a computer. A mouse rollover occurs when a cursor or pointer is moved over a graphical icon or designated “hot spot” on the screen of a computer's display device. Text corresponding to the icon or hot spot (which typically identifies the function or content represented by the icon or hot spot) appears automatically; the mouse (or other user input device) doesn't have to be clicked (or otherwise activated) for the text to appear. The mouse rollover technique is used in numerous computer programs, such as, for example, Adobe Photoshop. In Photoshop, for instance, a menu bar is included for the selection of various drawing and design tools. A graphical icon represents each tool. A picture of a paintbrush, for example, represents the paintbrush tool. Textual explanations for each tool appear on-screen as a pointer is moved over the corresponding graphical icon. Selecting (e.g., clicking a mouse or activating another input device) the graphical icon launches the tool.